There exist in today's market imaging devices capable of reading documents such as ID cards, drivers license, business cards, passports, medical cards and the like, and including booklet-type documents such as passports (hereinafter referred to, with no limitations, as “passport”). In imaging devices that include an imaging sensor array, based on technologies such as a CCD or CMOS, it is desired that the imaged document will be uniformly placed within the focal depth of the imaging sensor, in order to obtain a substantially true image of the imaged document.
The uniformity of the document illumination may affect the quality of an image, for example, by external ambient light sources. Such random illumination may, for example, cause hot spots in the formed image and/or shadows distortions. The type of light might also be a factor, for example, sun, electric bulb, florescent lighting, etc. Hence, most imaging devices do not operate in such “open environment”, containing random illumination sources.
Therefore, prior art imaging devices include substantially enclosed chambers (“closed environment”) that are designed to block ambient light (typically coming from random light sources) from illuminating the imaged document that typically, form spot lights in the image frame of the imaged document. By way of example, this problem is described in U.S. Pat. No. 7,948,665 given to Hatzav et al, in U.S. Pat. No. 8,136,966 given to Hatzav et al, in U.S. patent application Ser. No. 13/185,510 by Hatzav et al., in U.S. patent application Ser. No. 13/223,342 by Hatzav et al and in U.S. patent application Ser. No. 13/284,361 by Hatzav et al.
The document is typically placed on a substantially flat surface, wherein that flat surface faces the image sensor. For example, with no limitations, the imaging device includes at list one image sensor that faces down towards the flat surface. In this case, a passport is placed on top of the flat surface such that the desired page faces up towards the image sensor.
However, when placing an open passport with internal pages facing up, the pages tent to rise and the page to be imaged has to be forced to lie flat, facing up.
There is therefore a need and it would be advantageous to have a holding mechanism for imaging apparatus that keeps the imaged document, including a page in a booklet, flat and facing up towards the image sensor of the imaging apparatus.